Buffer material and buffer material structure

ABSTRACT

A buffer material is formed by assembling four buffer members containing cellulose fibers and having a plate shape, in which the cellulose fibers are oriented along a main surface of the buffer member, a first buffer member and a third buffer member among the four buffer members are spaced apart from each other and have the respective main surfaces disposed along each other, and a second buffer member and a fourth buffer member are spaced apart from each other and have the respective main surfaces disposed along each other, a rectangular frame shape is shown when viewed in a plan view from a direction along a Z axis, and an article is stored in a region surrounded by the four buffer members in the plan view.

The present application is based on, and claims priority from JP Application Serial Number 2022-110251, filed Jul. 8, 2022, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a buffer material and a buffer material structure.

2. Related Art

In the related art, a buffer material for storing an article, such as a fragile object, has been known. For example, JP-A-2009-280269 discloses a packing box including a box-shaped main body and a reinforcing member. In addition, JP-A-2013-170001 discloses five types of buffer materials for holding a liquid crystal television.

However, the packing box disclosed in JP-A-2009-280269 has a problem that labor is required for assembly, such as bending or fixing of the reinforcing member. In addition, the buffer material disclosed in JP-A-2013-170001 has a problem that the number of components is likely to be increased. That is, there has been a demand for a buffer material that has a simple configuration and is easily assembled.

SUMMARY

According to an aspect of the present disclosure, a buffer material is formed by assembling four buffer members containing cellulose fibers and having a plate shape, in which the cellulose fibers are oriented along a main surface of the buffer member, two buffer members among the four buffer members are spaced apart from each other and have the respective main surfaces disposed along each other, and the other two buffer members are spaced apart from each other and have the respective main surfaces disposed along each other, a rectangular frame shape is shown when viewed in a plan view from a direction orthogonal to a normal direction of all four main surfaces of the four buffer members, and an article is stored in a region surrounded by the four buffer members in the plan view.

According to another aspect of the present disclosure, a buffer material structure is formed by assembling four buffer members containing cellulose fibers and having a plate shape, in which the cellulose fibers are oriented along a main surface of the buffer member, two buffer members among the four buffer members are spaced apart from each other and have the respective main surfaces disposed along each other, and the other two buffer members are spaced apart from each other and have the respective main surfaces disposed along each other, a frame shape is shown when viewed in a plan view from a direction orthogonal to a normal direction of all four main surfaces of the four buffer members, and in the plan view, an article is stored in a region surrounded by the four buffer members.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a configuration of a sheet applied to a buffer member according to a first embodiment.

FIG. 2 is a schematic diagram showing a configuration of a test piece as an example used for a compression test.

FIG. 3 is a schematic diagram showing a configuration of a test piece as a comparative example used for a compression test.

FIG. 4 is a schematic diagram showing the configuration of the test piece as the comparative example used for the compression test.

FIG. 5 is a graph showing a compression ratio-stress curve of each test piece.

FIG. 6 is a diagram showing an appearance of the buffer member.

FIG. 7 is a perspective view showing an appearance of a buffer material.

FIG. 8 is a perspective view showing a use form of the buffer material.

FIG. 9 is a schematic diagram showing a configuration of a sheet manufacturing apparatus.

FIG. 10 is a diagram showing an appearance of a buffer member according to a second embodiment.

FIG. 11 is a perspective view showing an appearance of a buffer material.

FIG. 12 is a diagram showing an appearance of a buffer member according to a third embodiment.

FIG. 13 is a diagram showing an appearance of the buffer member.

FIG. 14 is a perspective view showing an appearance of a buffer material.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the embodiments described below, a buffer member formed by reusing waste paper or the like, and a buffer material and a buffer material structure formed from the buffer member will be shown and described with reference to the drawings. In each of the following drawings, XYZ axes, which are coordinate axes orthogonal to each other, or any one thereof is attached as necessary, and a direction indicated by an arrow is defined as a + direction, and a direction opposite to the + direction is defined as a − direction.

The directions of X, Y, and Z in FIG. 9 do not always match the directions of X, Y, and Z in the drawings other than FIG. 9 . In addition, for convenience of illustration, a size of each member is different from an actual size.

1. First Embodiment 1.1. Sheet

A buffer material 200 according to a first embodiment is formed by assembling a buffer member 201 produced from a sheet S. As shown in FIG. 1 , the sheet S is a member having a substantially rectangular plate shape. The sheet S has main surfaces f1 and f2 and side surfaces f3, f4, f5, and f6 facing each other. The side surfaces f3 and f4 face each other, and the side surfaces f5 and f6 face each other.

The sheet S contains a plurality of cellulose fibers FB. When the sheet S is viewed in a transmission view from a normal direction of the main surfaces f1 and f2, the plurality of cellulose fibers FB are not oriented in a specific direction. On the other hand, when the sheet S is viewed in the transmission view from a normal direction of the side surfaces f3 and f4 and a normal direction of the side surfaces f5 and f6, the plurality of cellulose fibers FB are oriented along the main surfaces f1 and f2. This orientation state is derived from a method of manufacturing the sheet S, which will be described below.

Due to the orientation state described above, the sheet S has low buffer performance with respect to an external force acting from the substantially normal direction of the main surfaces f1 and f2, and high buffer performance with respect to an external force acting from the substantially normal direction of the side surfaces f3 and f4 or the side surfaces f5 and f6.

Here, the buffer performance of the sheet S will be described by showing results of a compression test. FIG. 2 is a test piece TP1 as an example used in the compression test. The test piece TP1 is produced from the sheet S. In the test piece TP1, an orientation direction DS of the cellulose fibers FB is along the main surface f2 and is also along the main surface f1 (not shown). A compression force PW, which is the external force, is applied to the test piece TP1 from the normal direction of the side surface f3 in the compression test.

FIG. 3 shows a test piece TP2 as a comparative example used in the compression test. The test piece TP2 is produced from the sheet S. In the test piece TP2 as well, the orientation direction DS of the cellulose fibers FB is along the main surface f1. The compression force PW is applied to the test piece TP2 from the normal direction of the main surface f1 in the compression test.

FIG. 4 shows a test piece TP3 as a comparative example used in the compression test. The test piece TP3 is produced from expanded polystyrene. The compression force PW is applied to the test piece TP3 from the normal direction of the main surface f11 in the compression test.

Although not shown, a test piece TP4 is also used as a comparative example of the compression test. The test piece TP4 contains the plurality of cellulose fibers FB similarly to the test piece TP1, but the cellulose fibers FB are not oriented in the specific direction in the four directions described above in the transmission view. That is, in the test piece TP4, the plurality of cellulose fibers FB are randomly dispersed. The test piece TP4 is produced from a sheet in which the orientation direction of the cellulose fibers FB is dispersed and which has a lower density than the sheet S, by using a sheet manufacturing apparatus of the sheet S which will be described below.

The test pieces TP1, TP2, TP3, and TP4 have substantially cubic shapes having similar external dimensions. The test pieces TP1 and TP2 have a density of 0.15 g/cm³, a content of the cellulose fibers FB of 70% by mass, and a content of a binder and an additive of 30% by mass. The test piece TP4 has a density of 0.09 g/cm³, a content of the cellulose fibers FB of 67% by mass, and a content of a binder and an additive of 33% by mass.

Each of the test pieces described above is subjected to the compression test conforming to JIS K 7181 to measure a relationship between a compression ratio and stress. FIG. 5 shows the results. In FIG. 5 , a horizontal axis represents the compression ratio and a vertical axis represents the stress (MPa). The compression ratio is a value expressed as a percentage of a distance obtained by compressing each test piece in the direction in which the compression force PW acts by the compression force PW with respect to a thickness of each test piece in the direction in which the compression force PW acts in each test piece. The stress is a reaction force of each test piece that reacts to the compression force PW.

As shown in FIG. 5 , in the test pieces TP2 and TP4, the stress is increased relatively significantly as the compression ratio is increased. The reason is that the internal density is increased when a surface pressed by the compression force PW is depressed.

On the other hand, in the test pieces TP1 and TP3, the increase in stress is relatively smaller than the increase in compression ratio. The reason is derived from the fact that the internal density is less likely to be increased even when the surface pressed by the compression force PW is depressed. That is, the test pieces TP1 and TP3 are deformed when the compression force PW, such as an impact, is applied from the outside, but have a characteristic that the stress is less likely to be increased in the process of deformation.

As a result, it is found that the test piece TP1 of the example has more excellent buffer performance than the test pieces TP2 and TP4 of the comparative examples. In addition, it is found that the test piece TP1 has the buffer performance comparable to the buffer performance of the foamed styrene test piece TP3, which is the expanded polystyrene widely recognized as the buffer member. From the above, it is shown that the sheet S shown in FIG. 1 has excellent buffer performance against the external force acting from a direction intersecting the side surfaces f3, f4, f5, and f6.

1.2. Buffer Member

The buffer member 201 produced from the sheet S will be described. The buffer material 200 includes four buffer members 201. As shown in FIG. 6 , the buffer member 201 has a substantially rectangular plate shape. Here, FIG. 6 shows a state in which the buffer member 201 on the left side in the drawing is viewed in a side view from the normal direction of the main surface f1, and shows a state in which the buffer member 201 on the right side in the drawing is viewed in a side view from the normal direction of the side surface f5. In the buffer member 201, the main surfaces f1 and f2 match the same surface of the sheet S. In addition, the side surfaces f3, f4, and f5 of the buffer member 201 and the side surfaces f6 (not shown) are surfaces that match or are parallel to the same surface of the sheet S.

Although not shown, the buffer member 201 includes the plurality of cellulose fibers FB similarly to the sheet S. The plurality of cellulose fibers FB are oriented along the main surfaces f1 and f2 of the buffer member 201. The buffer material 200 is formed by assembling the four buffer members 201.

The four buffer members 201 have the same shape. Specifically, each buffer member 201 includes a first notch portion 211 a on a first side E1, and a second notch portion 211 b on a second side E2 that is along the first side E1 and faces the first side E1.

The first notch portion 211 a and the second notch portion 211 b are notches having a substantially rectangular shape. The first notch portion 211 a and the second notch portion 211 b are disposed diagonally on the buffer member 201 when the main surface f1 is viewed in the side view in the normal direction. That is, the buffer member 201 has a shape in which diagonal portions at the upper left and lower right of the rectangular shape are cut into an oblong. A long side of the oblong is along the Z axis.

In the first notch portion 211 a and the second notch portion 211 b, a width corresponding to the short side of the oblong described above, that is, a width A orthogonal to the first side E1 or the second side E2 is equal to or less than a thickness B of the buffer member 201. In addition, in a direction along the Z axis, which is a direction along the first side E1 and the second side E2, a sum of a depth L1 of the first notch portion 211 a and a depth L2 of the second notch portion 211 b is equal to or less than a length K of the buffer member 201 in the direction along the Z axis. Here, the depth L1 corresponds to the length of the long side of the oblong of the first notch portion 211 a, and the depth L2 corresponds to the length of the long side of the oblong of the second notch portion 211 b.

As a result, the assembled buffer material 200 is less likely to come apart, and it is possible to easily maintain the shape. The assembly of the buffer material 200 will be described below.

In the buffer member 201, the disposition, the shapes, and the like of the first notch portion 211 a and the second notch portion 211 b are not limited to the configuration described above. In addition, the thickness B, the length K, the length of the side adjacent to the first side E1 and the second side E2, and the like of the buffer member 201 are appropriately changed according to a size or a shape of an article stored in the buffer material 200. Although not particularly limited, for example, the thickness B is about 10 mm.

1.3. Buffer Material

As shown in FIG. 7 , the buffer material 200 is formed by assembling a first buffer member 201 a, a second buffer member 201 b, a third buffer member 201 c, and a fourth buffer member 201 d, which are the four buffer members 201, and has a buffer material structure described below. As described above, the first buffer member 201 a, the second buffer member 201 b, the third buffer member 201 c, and the fourth buffer member 201 d have the same shape.

Among the four buffer members 201, the first buffer member 201 a and the third buffer member 201 c, which are two buffer members 201, are disposed to be spaced apart from each other in the direction along the Y axis. The main surfaces f1 and f2 of each of the first buffer member 201 a and the third buffer member 201 c are along the XZ plane and along each other.

Among the four buffer members 201, the second buffer member 201 b and the fourth buffer member 201 d, which are the other two buffer members 201, are disposed to be spaced apart from each other in the direction along the X axis. The main surfaces f1 and f2 of each of the second buffer member 201 b and the fourth buffer member 201 d are along the YZ plane and along each other.

In the buffer material 200, the first buffer member 201 a, the second buffer member 201 b, the third buffer member 201 c, and the fourth buffer member 201 d are assembled as follows. In the first buffer member 201 a and the second buffer member 201 b, the second notch portion 211 b of the first buffer member 201 a and the first notch portion 211 a of the second buffer member 201 b are fitted together, and the main surfaces f1 thereof are orthogonal to each other.

In the second buffer member 201 b and the third buffer member 201 c, the second notch portion 211 b of the second buffer member 201 b and the first notch portion 211 a (not shown) of the third buffer member 201 c are fitted together, and the main surfaces f1 thereof are orthogonal to each other. Although not shown, in the third buffer member 201 c and the fourth buffer member 201 d, the second notch portion 211 b of the third buffer member 201 c and the first notch portion 211 a of the fourth buffer member 201 d are fitted together, and the main surfaces f1 thereof are orthogonal to each other. In the fourth buffer member 201 d and the first buffer member 201 a, the second notch portion 211 b (not shown) of the fourth buffer member 201 d and the first notch portion 211 a of the first buffer member 201 a are fitted together, and the main surfaces f1 thereof are orthogonal to each other.

The buffer material 200 shows a rectangular frame shape when viewed in a plan view from a direction orthogonal to all normal directions of the four main surfaces f1 of the four buffer members 201, that is, the direction along the Z axis. In the buffer material 200, the article (not shown) is stored in a region 200 p surrounded by the four buffer members 201. The buffer material according to the present disclosure is not limited to being the rectangular shape in the plan view described above, and may be, for example, a triangular shape or a polygonal shape. In this case, the number of buffer members 201 is increased or decreased according to the shape.

Examples of the article stored in the buffer material 200 include fragile objects, such as pottery, porcelain, and glassware, as well as information terminal devices, such as a watch, a laptop computer, a small game machine, a smartphone, a printer, and a projector, a precision component, a model, a home appliance, and fruits and vegetables.

The buffer material 200 can be regarded as a cube. Therefore, in a state in which the article is stored in the region 200 p, a plurality of buffer materials 200 may be stacked and placed, or the plurality of buffer materials 200 may be packed together.

The buffer material 200 faces a surface other than the main surfaces f1 and f2, that is, any of the side surfaces f5 and f6 with respect to directions along the X axis and the Y axis. Therefore, when the external force acts on the buffer material 200 from a direction substantially along the X axis and the Y axis, it is possible to receive the external force on any of the side surfaces f5 and f6.

In addition, the buffer material 200 faces any of the side surfaces f3 and f4 with respect to the direction along the Z axis. Therefore, when the external force acts on the buffer material 200 from a direction substantially along the Z axis, it is possible to receive the external force on any of the side surfaces f3 and f4. As described above, the buffer material 200 protects the article stored in the region 200 p by the buffer performance against the external force acting from the direction substantially along each of XYZ axes.

As shown in FIG. 8 , the buffer material 200 may be accommodated in an outer box 290 in a detachable manner. As a result, the article stored in the region 200 p of the buffer material 200 can be prevented from staining. Also, the buffer material 200 in which the article is stored can be easily handled or stored. Materials, such as corrugated board, thick paper, and resin, are applied to the outer box 290.

When the buffer material 200 is accommodated in the outer box 290, it is preferable that the external dimensions of the buffer material 200 match the internal dimensions of the outer box 290. As a result, the buffer material 200 can be steadily accommodated in the outer box 290.

1.4. Sheet Manufacturing Apparatus

A method of manufacturing the sheet S and the buffer member 201 will be described together with a configuration of a sheet manufacturing apparatus 1. In the following description of the sheet manufacturing apparatus 1, a destination of a transport direction of a raw material, the web, or the like may be referred to as downstream, and a side that goes back in the transport direction may be referred to as upstream. The method of manufacturing the sheet S and the buffer member 201 and the sheet manufacturing apparatus 1 described below are merely examples, and the present disclosure is not limited to this.

As shown in FIG. 9 , the sheet manufacturing apparatus 1 includes, from an upstream part toward a downstream part, a material supply section 5, a crushing section 10, a defibration section 30, a pipe 40, a supply member 42, a forming section 100, a web transport section 70, a molding section 150, and a cutting section 160. In the following description of FIG. 9 , a +Z direction may be referred to as an upward direction, and a −Z direction may be referred to as a downward direction.

The sheet manufacturing apparatus 1 includes a control section 28 that integrally controls the operation of each of the configurations. The sheet manufacturing apparatus 1 manufactures the sheet S that is a molded product having a sheet shape. A thickness of the sheet S is not particularly limited as long as the buffer member 201 produced from the sheet S exhibits the buffer performance. The thickness of the sheet S and the buffer member 201 is about 10 mm, for example. The thickness herein is a distance in the direction along the Z axis in FIG. 9 .

The material supply section 5 supplies a raw material C to the crushing section 10. The material supply section 5 includes an automatic feeding mechanism, and the raw material C is continuously and automatically charged into the crushing section 10. The raw material C is a material containing the cellulose fibers FB. The material containing the cellulose fibers FB is, for example, waste paper, such as paper and corrugated board, pulp, pulp sheet, sawdust, shavings, wood, and fabric.

By defibrating such the raw material C by the defibration section 30, which will be described below, the cellulose fibers FB are obtained as defibrated materials. The cellulose fibers FB are fibers contained in plant fibers such as wood and are carbohydrates. The cellulose fiber FB is one of the main components of the sheet S manufactured by the sheet manufacturing apparatus 1. The sheet S may contain synthetic fibers, such as polypropylene, polyester, and polyurethane, in addition to the cellulose fibers FB. From the viewpoint of reducing the environmental load, it is preferable to use fibers derived from natural products, such as the cellulose fibers FB. Hereinafter, the cellulose fibers FB and the like applied to the sheet S are collectively and simply referred to as fibers.

The crushing section 10 shreds the raw material C supplied from the material supply section 5 in the air, such as the atmosphere. The crushing section 10 has a crushing blade 11. The crushing section 10 is, for example, a shredder or a cutter mill. The raw material C is shredded by the crushing blade 11 into fragments. A planar shape of the fragment is, for example, several mm square or irregular. The fragments are collected in a fixed-quantity material supply section 50.

The fixed-quantity material supply section 50 weighs the fragments and supplies the fragments to a hopper 12 in a fixed quantity. The fixed-quantity material supply section 50 is, for example, a vibration feeder. The fragments supplied to the hopper 12 are transported to an introduction port 31 of the defibration section 30 through the pipe 20.

The defibration section 30 includes an introduction port 31, a discharge port 32, a stator 33, and a rotor 34. The defibration section 30 defibrates the fragments of the raw material C by a dry method to produce the fibers. The fragments of the raw material C are introduced into an inside of the defibration section 30 through the introduction port 31 by a suction airflow of an air blowing section 41, which will be described below. In the present specification, the dry method means that it is carried out in the air, such as the atmosphere, not in the liquid.

The stator 33 and the rotor 34 are disposed inside the defibration section 30. The stator 33 has an inner side surface having a substantially cylindrical shape. The rotor 34 rotates along the inner side surface of the stator 33. The fragments of the raw material C are interposed between the stator 33 and the rotor 34, and are defibrated by a shearing force generated between the stator 33 and the rotor 34 to be the fibers. The fibers are sucked into the pipe 40 from the discharge port 32 of the defibration section 30 by the suction airflow.

It is preferable that the fibers produced by the defibration have a fiber length of 1.0 mm or more. Accordingly, since the fibers are not excessively shortened, a mechanical strength of the sheet S is improved. The fiber length is obtained by a method conforming to ISO 16065-2: 2007.

The pipe 40 communicates with the inside of the defibration section 30 and an inside of the supply member 42. The pipe 40 is provided with a mixing section 60 and the air blowing section 41. The mixing section 60 is disposed upstream of the air blowing section 41. The pipe 40 supplies a mixture, which is a material containing the fibers and will be described below, to the supply member 42 by a downstream airflow generated by the air blowing section 41.

The mixing section 60 includes hoppers 13 and 14, supply pipes 61 and 62, and valves 65 and 66. The mixing section 60 mixes a binder and an additive with the material, such as the fibers, transported in the air of the pipe 40. As a result, the mixture is produced.

The hopper 13 supplies the binder into the pipe 40. The hopper 13 communicates with an inside of the pipe 40 through the supply pipe 61. The valve 65 is disposed between the hopper 13 and the pipe 40 in the supply pipe 61. The valve 65 adjusts the weight of the binder supplied from the hopper 13 to the pipe 40. The valve 65 adjusts a mixing ratio between the fibers and the binder. The binder may be supplied as a powder, or may be melted and supplied.

The binder binds the fibers together. As the binder, a resin having thermal plasticity or thermosetting property is used. Examples of the resin include resins derived from natural products, such as shellac, pine resin, dammar, polylactic acid, polybutylene succinate derived from a plant, polyethylene derived from a plant, and PHBH (registered trademark) (poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)) manufactured by KANEKA CORPORATION, and known synthetic resins. As the binder, one of these types may be used alone, or in combination of two or more types. From the viewpoint of reducing the environmental load, it is preferable that the binder is a resin derived from natural products.

The hopper 14 supplies the additive into the pipe 40. The hopper 14 communicates with the inside of the pipe 40 through the supply pipe 62. The valve 66 is disposed between the hopper 14 and the pipe 40 in the supply pipe 62. The valve 66 adjusts the weight of the additive supplied from the hopper 14 to the pipe 40. The valve 66 adjusts a mixing ratio of the additive to the fibers and the binder.

Examples of the additive include a colorant, a flame retardant, an antioxidant, an ultraviolet absorber, an aggregation inhibitor, an antibacterial agent, an antifungal agent, a wax, and a mold release agent. The additive is not an essential component in the sheet S, and the hopper 14, the supply pipe 62, or the like may be omitted. In addition, the additive may be mixed with the binder in advance and supplied from the hopper 13.

The air blowing section 41 is an airflow generator, such as a blower. The air blowing section 41 transports the material containing the fibers to the downstream pipe 40 by the downstream airflow. In addition to the airflow, the air blowing section 41 also generates the suction airflow for sucking the fibers from the defibration section 30. A volumetric flow rate of the airflow going downstream of the air blowing section 41 is controlled by the control section 28. The volumetric flow rate can be changed, for example, by a rotation speed of an air blowing fan provided in the air blowing section 41.

The fibers, the binder, and the like are mixed while being transported to the supply member 42 in the pipe 40 to form the mixture. The mixture is introduced into the supply member 42 that couples a downstream end of the pipe 40 to the forming section 100.

The supply member 42 rectifies a flow of the mixture supplied from the pipe 40 and guides the mixture to the forming section 100. The supply member 42 is coupled to a dispersion section 101 of the forming section 100. Specifically, the inside of the supply member 42 communicates with an inside of a drum section 101 b of the dispersion section 101. As a result, the mixture flows into the drum section 101 b from the supply member 42.

The forming section 100 forms a web W by accumulating the mixture containing the fibers, the binder, and the like in the air. The web W has a wide band shape in the direction along the Y axis. The forming section 100 includes the dispersion section 101 and an accumulation section 102. The dispersion section 101 is disposed inside the accumulation section 102. The inside of the dispersion section 101 communicates with the pipe 40 through the supply member 42. The web transport section 70 is disposed below the accumulation section 102.

The dispersion section 101 includes a rotating member 101 a and a drum section 101 b for accommodating the rotating member 101 a. The forming section 100 takes the mixture from the supply member 42 into the inside of the dispersion section 101, and accumulates the mixture on a mesh belt 122 of the web transport section 70 by a dry method.

Specifically, the rotating member 101 a is a member including a + shaped blade in a side view from a −Y direction. The rotating member 101 a rotates around a rotation axis along the Y axis as a rotation center by driving a motor or the like.

The drum section 101 b is a member having a substantially columnar shape, and a height direction of the substantially columnar shape is along the Y axis. A lower part of the drum section 101 b is formed of a metal mesh. The mesh of the metal mesh allows the fibers, the binder, or the like contained in the mixture to pass through.

The mixture (not shown) is introduced into the drum section 101 b and unraveled by the rotating member 101 a that rotates. A plurality of fibers in the mixture are released from an entangled state, separated into a single body, and pass through the mesh of the drum section 101 b. As a result, the dispersion section 101 disperses the fibers, the binder, and the like contained in the mixture into the air in the accumulation section 102.

The accumulation section 102 is a member having a substantial box shape. The accumulation section 102 is disposed below the dispersion section 101. In the accumulation section 102, the supply member 42 is disposed above an upper surface, and the dispersion section 101 is disposed on an inner side of the upper surface. A region corresponding to a bottom surface of the accumulation section 102 is opened downward. The dispersion section 101 is inside the accumulation section 102 and faces an upper surface of the mesh belt 122 of the web transport section 70. The accumulation section 102 is formed of a resin or a metal, for example.

The mixture is discharged from the inside of the dispersion section 101 into the air inside the accumulation section 102, and is guided above the mesh belt 122 by gravity and a suction force of a suction mechanism 110. Therefore, the mixture is accumulated on the upper surface of the mesh belt 122 through a first base material N1, which will be described below. That is, the accumulation section 102 accumulates the mixture containing the dispersed fibers to form the web W.

With the configuration described above, in the web W, the plurality of fibers are oriented along the XY plane. That is, a base of the orientation state of the sheet S is formed in which the plurality of fibers are along the main surfaces f1 and f2.

The web transport section 70 includes the mesh belt 122 and the suction mechanism 110. The mesh belt 122 is an endless belt and is stretched by four stretch rollers 121.

The mesh belt 122 has a strength capable of holding the web W and the like without interfering with the suction by the suction mechanism 110. The mesh belt 122 is formed of a resin or a metal, for example. A hole diameter of the mesh included in the mesh belt 122 is not particularly limited, but is desirably 60 μm or more and 125 μm or less.

At least one of the four stretch rollers 121 is rotationally driven by a motor (not shown). The upper surface of the mesh belt 122 is moved downstream due to the rotation of the stretch roller 121. Stated another way, the mesh belt 122 moves rotationally clockwise in FIG. 9 . By the mesh belt 122 moving rotationally, the first base material N1 and the web W, which will be described below, are transported downstream.

A base material supply section 71 is disposed in the −X direction of the web transport section 70. The base material supply section 71 rotatably supports the first base material N1 having a roll shape. The first base material N1 is continuously supplied from the base material supply section 71 to the upper surface of the mesh belt 122.

The first base material N1 interposes the web W with a second base material N2, which will be described below. For example, for the first base material N1 and the second base material N2, a woven fabric or a non-woven fabric is applied. It is preferable that the first base material N1 has a configuration that does not interfere with the suction of the suction mechanism 110. For example, for the first base material N1 and the second base material N2, a polyester long fiber nonwoven fabric manufactured by a spunbond method is applied.

The sheet S is formed by laminating the first base material N1, the web W, and the second base material N2, so that the mechanical strength is improved. In the sheet S, the first base material N1 and the second base material N2 are not essential configurations, and any one or both thereof may be omitted.

When the base material supply section 71 supplies the first base material N1 to the mesh belt 122, the first base material N1 is transported on the mesh belt 122 in the +X direction. In the first base material N1 while being transported, the mixture is fallen from the accumulation section 102 and accumulated on the upper surface. As a result, the web W is continuously formed on the upper surface of the first base material N1. The mesh belt 122 transports the web W downstream together with the first base material N1.

The suction mechanism 110 is disposed below the dispersion section 101. The suction mechanism 110 promotes the accumulation of the mixture on the mesh belt 122. The suction mechanism 110 sucks the air into the accumulation section 102 through a plurality of holes included in the mesh belt 122 and the first base material N1. The plurality of holes in the mesh belt 122 and the first base material N1 allow the air to pass through, and make it difficult for the fibers, the binder, or the like contained in the mixture to pass through. The mixture discharged from the dispersion section 101 to an inner side of the accumulation section 102 is sucked downward together with the air. A known suction device, such as a blower, is adopted for the suction mechanism 110.

As a result, the mixture in the accumulation section 102 is accumulated on the upper surface of the first base material N1 by the suction force of the suction mechanism 110 in addition to the gravity, to form the web W. The web W contains a relatively large amount of the air and is soft and swollen. By the mesh belt 122, the web W is transported downstream together with the first base material N1.

A humidifying section 139 is provided at a position facing the web W above the mesh belt 122 in the +X direction of the accumulation section 102. The humidifying section 139 sprays water onto the web W on the mesh belt 122 to humidify the web W. As a result, scattering of the fibers, the binder, or the like contained in the web W can be suppressed. In addition, the water used for the humidification may be impregnated with a water-soluble additive or the like, and the web W may be impregnated with the additive in parallel with the humidification.

A dancer roller 141 is disposed downstream of the web transport section 70. The web W is peeled from the most downstream stretch roller 121, and then pulled into the dancer roller 141. The dancer roller 141 secures a processing time on the downstream part. Specifically, molding in the molding section 150 is a batch process. Therefore, the dancer roller 141 is moved up and down with respect to the web W continuously transported from the accumulation section 102, and a time for reaching the molding section 150 is delayed.

The base material supply section 72 is disposed downstream of the dancer roller 141 and upstream of the molding section 150. The base material supply section 72 rotatably supports the second base material N2 having a roll shape. The second base material N2 is continuously supplied from the base material supply section 72 to the upper surface of the web W. As a result, the web W is fed out to the molding section 150 in a state of being interposed between the lower first base material N1 and the upper second base material N2.

The molding section 150 is a heat pressing device, and includes an upper substrate 152 and a lower substrate 151. The molding section 150 molds the first base material N1, the web W, and the second base material N2 into the sheet S having a continuous paper shape. The upper substrate 152 and the lower substrate 151 are pressurized with the web W interposed therebetween, and are heated by a built-in heater.

The web W is compressed from above and below by the pressurization to be increased in the density, and the binder is melted by the heating and spreads wet between the fibers. When the heating ends in this state and the binder is solidified, the fibers are bound to each other by the binder. As a result, the sheet S having a continuous paper shape, which is composed of three layers of the first base material N1, the web W, and the second base material N2, is molded. In this case, the orientation state of the sheet S is fixed. The sheet S having a continuous paper shape proceeds to the downstream cutting section 160.

In the molding section 150, instead of the heat pressing device, a heating roller and a pressurization roller may be used for continuous molding. In this case, the dancer roller 141 may be omitted.

The cutting section 160 cuts the sheet S from a continuous paper shape to a single paper shape. Although not shown, the cutting section 160 includes a vertical blade and a horizontal blade. The vertical blade and the horizontal blade are rotary cutters, for example. In addition, an ultrasound cutter or the like may be used instead of the rotary cutter.

The vertical blade cuts the sheet S having a continuous paper shape in a direction along the traveling direction. The horizontal blade cuts the sheet S having a continuous paper shape in a direction intersecting the traveling direction. The sheet S is processed into a substantially rectangular single paper shape and accommodated in a tray 170. In this way, the sheet S is manufactured.

The sheet manufacturing apparatus 1 may include a processing unit (not shown) downstream of the cutting section 160 or the tray 170. The processing unit forms the first notch portion 211 a and the second notch portion 211 b on the sheet S having the single paper shape. For example, a wheel cutter, a partial cutter, a Thomson type (Vic type), and the like are applied to the processing unit. The buffer member 201 may be produced from the sheet S by another apparatus.

According to the present embodiment, it is possible to obtain the following effects.

The buffer material 200 that is easily assembled with a simple configuration can be obtained. Specifically, since the buffer material 200 is formed by assembling the four buffer members 201, the labor required for assembly is reduced as compared with the related art. In addition, the number of components is smaller than in the related art, and the configuration is simple. Accordingly, it is possible to provide the buffer material 200 and the buffer material structure which are easily assembled with a simple configuration.

Since the four buffer members 201 have the same shape, the type of component is one type and can be used for common use. In addition, since the assembly is made by fitting the first notch portion 211 a and the second notch portion 211 b together, misalignment or the like is unlikely to occur, and the buffer material 200 can be steadily assembled.

2. Second Embodiment

A buffer material 300 according to a second embodiment is formed by assembling a buffer member 301 produced from the sheet S. In the buffer material 300 according to the present embodiment, the buffer member 301 having a shape different from the shape of the buffer member 201 is applied to the buffer material 200 according to the first embodiment. In the following description, a configuration different from the first embodiment will be described, and a configuration overlapping the first embodiment will be omitted.

The buffer material 300 includes four buffer members 301. As shown in FIG. 10 , the buffer member 301 has a substantially rectangular plate shape. Here, FIG. 10 shows a state in which the buffer member 301 on the left side in the drawing is viewed in the side view from the normal direction of the main surface f1, and shows a state in which the buffer member 301 on the right side in the drawing is viewed in the side view from the normal direction of the side surface f5. In the buffer member 301, the main surfaces f1 and f2 match the same surface of the sheet S. In addition, the side surfaces f3, f4, and f5 of the buffer member 301 and the side surfaces f6 (not shown) are surfaces that match or are parallel to the same surface of the sheet S.

The buffer material 300 is formed by assembling the four buffer members 301. The four buffer members 301 have the same shape. Specifically, each buffer member 301 includes a recess portion 311 a on the first side E1, and a protrusion portion 311 b on the second side E2 that is along the first side E1 and faces the first side E1.

The recess portion 311 a and the protrusion portion 311 b are disposed in a shape that can be fitted together and at corresponding positions. Specifically, the recess portion 311 a and the protrusion portion 311 b are disposed to face each other in a direction orthogonal to the first side E1 and the second side E2 when the main surface f1 is viewed in the side view from the normal direction. The recess portion 311 a and the protrusion portion 311 b are disposed substantially at the center of the first side E1 or the second side E2 in the direction along the Z axis. The recess portion 311 a is a recess having a substantially rectangular shape, and the protrusion portion 311 b is a protrusion having a substantially rectangular shape. The recess and the protrusion have shapes that overlap in a plane.

A width A1 of the recess portion 311 a in the direction orthogonal to the first side E1 and a width A2 of the protrusion portion 311 b in the direction orthogonal to the second side E2 are substantially equal. Although not shown, the length of the recess portion 311 a along the first side E1 and the length of the protrusion portion 311 b along the second side E2 are substantially equal. In the buffer member 301, the disposition, the shapes, and the like of the recess portion 311 a and the protrusion portion 311 b are not limited to the configuration described above.

As shown in FIG. 11 , the buffer material 300 is formed by assembling a first buffer member 301 a, a second buffer member 301 b, a third buffer member 301 c, and a fourth buffer member 301 d, which are the four buffer members 301, and has a buffer material structure described below. As described above, the first buffer member 301 a, the second buffer member 301 b, the third buffer member 301 c, and the fourth buffer member 301 d have the same shape.

Among the four buffer members 301, the first buffer member 301 a and the third buffer member 301 c, which are two buffer members 301, are disposed to be spaced apart from each other in the direction along the Y axis. The main surfaces f1 and f2 of each of the first buffer member 301 a and the third buffer member 301 c are along the XZ plane and along each other.

Among the four buffer members 301, the second buffer member 301 b and the fourth buffer member 301 d, which are the other two buffer members 301, are disposed to be spaced apart from each other in the direction along the X axis. The main surfaces f1 and f2 of each of the second buffer member 301 b and the fourth buffer member 301 d are along the YZ plane and along each other.

In the buffer material 300, the first buffer member 301 a, the second buffer member 301 b, the third buffer member 301 c, and the fourth buffer member 301 d are assembled as follows. In the first buffer member 301 a and the second buffer member 301 b, the protrusion portion 311 b of the first buffer member 301 a and the recess portion 311 a of the second buffer member 301 b are fitted together, and the main surfaces f1 thereof are orthogonal to each other.

In the second buffer member 301 b and the third buffer member 301 c, the protrusion portion 311 b of the second buffer member 301 b and the recess portion 311 a of the third buffer member 301 c are fitted together, and the main surfaces f1 thereof are orthogonal to each other. Although not shown, in the third buffer member 301 c and the fourth buffer member 301 d, the protrusion portion 311 b of the third buffer member 301 c and the recess portion 311 a of the fourth buffer member 301 d are fitted together, and the main surfaces f1 thereof are orthogonal to each other. In the fourth buffer member 301 d and the first buffer member 301 a, the protrusion portion 311 b of the fourth buffer member 301 d and the recess portion 311 a of the first buffer member 301 a are fitted together, and the main surfaces f1 thereof are orthogonal to each other.

The buffer material 300 shows a rectangular frame shape when viewed in a plan view from a direction orthogonal to all normal directions of the four main surfaces f1 of the four buffer members 301, that is, the direction along the Z axis. In the buffer material 300, the article (not shown) is stored in a region 300 p surrounded by the four buffer members 301.

The buffer material 300 faces a surface other than the main surfaces f1 and f2, that is, any of the side surfaces f5 and f6 with respect to directions along the X axis and the Y axis. Therefore, when the external force acts on the buffer material 300 from a direction substantially along the X axis and the Y axis, it is possible to receive the external force on any of the side surfaces f5 and f6.

In addition, the buffer material 300 faces any of the side surfaces f3 and f4 with respect to the direction along the Z axis. Therefore, when the external force acts on the buffer material 300 from a direction substantially along the Z axis, it is possible to receive the external force on any of the side surfaces f3 and f4. As described above, the buffer material 300 protects the article stored in the region 300 p by the buffer performance against the external force acting from the direction substantially along each of XYZ axes.

According to the present embodiment, the same effects as the effects of the first embodiment can be obtained.

3. Third Embodiment

A buffer material 400 according to a third embodiment is formed by assembling a buffer member 401 produced from the sheet S. In the buffer material 400 according to the present embodiment, the buffer members 401 a and 401 b having a different shape from the shape of the buffer member 201 are applied to the buffer material 200 according to the first embodiment. In the following description, a configuration different from the first embodiment will be described, and a configuration overlapping the first embodiment will be omitted.

The buffer material 400 includes four buffer members 401. The four buffer members 401 include two types of buffer members 401 a and 401 b. The buffer member 401 a includes a first buffer member 401 a 1 and a third buffer member 401 a 2, which will be described below. The buffer member 401 b includes a second buffer member 401 b 1 and a fourth buffer member 401 b 2, which will be described below.

As shown in FIG. 12 , the buffer member 401 a has a substantially rectangular plate shape. Here, FIG. 12 shows a state in which the buffer member 401 a on the left side in the drawing is viewed in the side view from the normal direction of the main surface f1, and shows a state in which the buffer member 401 a on the right side in the drawing is viewed in the side view from the normal direction of the side surface f5. In the buffer member 401 a, the main surfaces f1 and f2 match the same surface of the sheet S. In addition, the side surfaces f3, f4, and f5 of the buffer member 401 a and the side surfaces f6 (not shown) are surfaces that match or are parallel to the same surface of the sheet S.

The buffer member 401 a, that is, the first buffer member 401 a 1 and the third buffer member 401 a 2 have the same shape having a first recess portion 411 a on the first side E1, and a second recess portion 411 b on the second side E2 that is along the first side E1 and faces the first side E1.

Specifically, the first recess portion 411 a and the second recess portion 411 b are disposed to face each other in a direction orthogonal to the first side E1 and the second side E2 when the main surface f1 is viewed in the side view from the normal direction. The first recess portion 411 a and the second recess portion 411 b are disposed substantially at the center of the first side E1 or the second side E2 in the direction along the Z axis. The first recess portion 411 a and the second recess portion 411 b are recesses having a substantially rectangular shape.

The width A1 of the first recess portion 411 a in the direction orthogonal to the first side E1 and the width A2 of the second recess portion 411 b in the direction orthogonal to the second side E2 are substantially equal. The widths A1 and A2 are equal to or less than the thickness B of the buffer member 401 a. Although not shown, the length of the first recess portion 411 a along the first side E1 and the length of the second recess portion 411 b along the second side E2 are substantially equal. In the buffer member 401 a, in a direction along the main surface f1 and orthogonal to the Z axis, a length of a region other than the first recess portion 411 a and the second recess portion 411 b is a length M. The length M is equal to a length of a long side of the buffer member 401 a.

As shown in FIG. 13 , the buffer member 401 b has a substantially rectangular plate shape. Here, FIG. 13 shows a state in which the buffer member 401 b on the left side in the drawing is viewed in the side view from the normal direction of the main surface f1, and shows a state in which the buffer member 401 b on the right side in the drawing is viewed in the side view from the normal direction of the side surface f5. In the buffer member 401 b, the main surfaces f1 and f2 match the same surface of the sheet S. In addition, the side surfaces f3, f4, and f5 of the buffer member 401 b and the side surfaces f6 (not shown) are surfaces that match or are parallel to the same surface of the sheet S.

The buffer member 401 b, that is, the second buffer member 401 b 1 and the fourth buffer member 401 b 2 have the same shape having a first protrusion portion 411 c on a third side E3, and a second protrusion portion 411 d on a fourth side E4 that is along the third side E3 and faces the third side E3.

Specifically, the first protrusion portion 411 c and the second protrusion portion 411 d are disposed to face each other in a direction orthogonal to the third side E3 and the fourth side E4 when the main surface f1 is viewed in the side view from the normal direction. The first protrusion portion 411 c and the second protrusion portion 411 d are disposed substantially at the center of the third side E3 or the fourth side E4 in the direction along the Z axis. The first protrusion portion 411 c and the second protrusion portion 411 d are protrusions having a substantially rectangular shape. The recess portion of the buffer member 401 a and the protrusion portion of the buffer member 401 b have shapes that overlap in a plane.

A width A3 of the first protrusion portion 411 c in a direction orthogonal to the third side E3 and a width A4 of the second protrusion portion 411 d in a direction orthogonal to the fourth side E4 are substantially equal. The widths A3 and A4 are equal to or less than the thickness B of the buffer member 401 b. Although not shown, the length of the first protrusion portion 411 c along the third side E3 and the length of the second protrusion portion 411 d along the fourth side E4 are substantially equal, and the length of the first recess portion 411 a along the first side E1 and the length of the second recess portion 411 b along the second side E2 are substantially equal.

In the buffer member 401 b, in the direction along the main surface f1 and orthogonal to the Z axis, the length M from a distal end of the first protrusion portion 411 c to a distal end of the second protrusion portion 411 d is equal to the length M in the buffer member 401 a. Here, the disposition, the shapes, and the like of the first recess portion 411 a and the second recess portion 411 b of the buffer member 401 a, and the first protrusion portion 411 c and the second protrusion portion 411 d of the buffer member 401 b are not limited to the configuration described above.

As shown in FIG. 14 , the buffer material 400 is formed by assembling the first buffer member 401 a 1, the second buffer member 401 b 1, the third buffer member 401 a 2, and the fourth buffer member 401 b 2, which are the four buffer members 401, and has a buffer material structure described below.

The first buffer member 401 a 1 and the third buffer member 401 a 2, which are the two buffer members 401 a, are disposed to be spaced apart from each other in the direction along the Y axis. The main surfaces f1 and f2 of each of the first buffer member 401 a 1 and the third buffer member 401 a 2 are along the XZ plane.

The second buffer member 401 b 1 and the fourth buffer member 401 b 2, which are the two buffer members 401 b, are disposed to be spaced apart from each other in the direction along the X axis. The main surfaces f1 and f2 of each of the second buffer member 401 b 1 and the fourth buffer member 401 b 2 are along the YZ plane.

When the buffer material 400 is assembled, the first side E1 of the first buffer member 401 a 1 and the third side E3 of the second buffer member 401 b 1 are disposed along each other. In addition, in the direction along the first side E1, that is, the direction along the Z axis, the first recess portion 411 a, the second recess portion 411 b, the first protrusion portion 411 c, and the second protrusion portion 411 d are disposed to correspond to each other.

Specifically, the second recess portion 411 b of the first buffer member 401 a 1 and the first protrusion portion 411 c of the second buffer member 401 b 1 are fitted together. The second protrusion portion 411 d of the second buffer member 401 b 1 and the first recess portion 411 a of the third buffer member 401 a 2 are fitted together. The second recess portion 411 b (not shown) of the third buffer member 401 a 2 and the first protrusion portion 411 c (not shown) of the fourth buffer member 401 b 2 are fitted together. The second protrusion portion 411 d of the fourth buffer member 401 b 2 and the first recess portion 411 a of the first buffer member 401 a 1 are fitted together. As a result, the buffer material 400 is assembled.

The article is stored in a region 400 p surrounded by the first buffer member 401 a 1, the second buffer member 401 b 1, the third buffer member 401 a 2, and the fourth buffer member 401 b 2.

According to the present embodiment, it is possible to obtain the following effects.

The buffer material 400 that is easily assembled with a simple configuration can be obtained. Specifically, since the buffer material 400 is formed by assembling the two buffer members 401 a and the two buffer members 401 b, the labor required for assembly is reduced as compared with the related art. In addition, the number of components is smaller than in the related art, and the configuration is simple. Accordingly, it is possible to provide the buffer material 400 and the buffer material structure which are easily assembled with a simple configuration.

There are two types of components, and the number of types can be reduced as compared with the related art. In addition, since the assembly is made by fitting, misalignment is unlikely to occur, and the assembly can be easily made. 

What is claimed is:
 1. A buffer material formed by assembling four buffer members containing cellulose fibers and having a plate shape, wherein the cellulose fibers are oriented along a main surface of the buffer member, two buffer members among the four buffer members are spaced apart from each other and have the respective main surfaces disposed along each other, and the other two buffer members are spaced apart from each other and have the respective main surfaces disposed along each other, a rectangular frame shape is shown when viewed in a plan view from a direction orthogonal to a normal direction of all four main surfaces of the four buffer members, and an article is stored in a region surrounded by the four buffer members in the plan view.
 2. The buffer material according to claim 1, wherein the four buffer members have the same shape having a first notch portion on a first side and a second notch portion on a second side that is along the first side and faces the first side, the first notch portion and the second notch portion are disposed diagonally in the buffer member when the main surface is viewed in a side view from the normal direction, the four buffer members include a first buffer member, a second buffer member, a third buffer member, and a fourth buffer member, and the buffer material is assembled by fitting the second notch portion of the first buffer member and first notch portion of the second buffer member together, fitting the second notch portion of the second buffer member and the first notch portion of the third buffer member together, fitting the second notch portion of the third buffer member and the first notch portion of the fourth buffer member together, and fitting the second notch portion of the fourth buffer member and the first notch portion of the first buffer member together.
 3. The buffer material according to claim 2, wherein in the first notch portion and the second notch portion, a width A orthogonal to the first side or the second side is equal to or less than a thickness B of the buffer member, and in a direction along the first side, a sum of a depth L1 of the first notch portion and a depth L2 of the second notch portion is equal to or less than a length K of the buffer member.
 4. The buffer material according to claim 1, wherein the four buffer members have the same shape having a recess portion on a first side and a protrusion portion on a second side that is along the first side and faces the first side, the recess portion and the protrusion portion are disposed to face each other in a direction orthogonal to the first side and the second side when the main surface is viewed in a side view from the normal direction, the four buffer members include a first buffer member, a second buffer member, a third buffer member, and a fourth buffer member, and the buffer material is assembled by fitting the protrusion portion of the first buffer member and the recess portion of the second buffer member together, fitting the protrusion portion of the second buffer member and the recess portion of the third buffer member together, fitting the protrusion portion of the third buffer member and the recess portion of the fourth buffer member together, and fitting the protrusion portion of the fourth buffer member and the recess portion of the first buffer member together.
 5. The buffer material according to claim 1, wherein the four buffer members include a first buffer member, a second buffer member, a third buffer member, and a fourth buffer member, the first buffer member and the third buffer member have the same shape having a first recess portion on a first side and a second recess portion on a second side that is along the first side and faces the first side, the second buffer member and the fourth buffer member have the same shape having a first protrusion portion on a third side and a second protrusion portion on a fourth side that is along the third side and faces the third side, the first side and the third side are disposed along each other, the first recess portion, the second recess portion, the first protrusion portion, and the second protrusion portion are disposed to correspond to each other in a direction along the first side, and the buffer material is assembled by fitting the second recess portion of the first buffer member and the first protrusion portion of the second buffer member together, fitting the second protrusion portion of the second buffer member and the first recess portion of the third buffer member together, fitting the second recess portion of the third buffer member and the first protrusion portion of the fourth buffer member together, and fitting the second protrusion portion of the fourth buffer member and the first recess portion of the first buffer member together.
 6. A buffer material structure formed by assembling four buffer members containing cellulose fibers and having a plate shape, wherein the cellulose fibers are oriented along a main surface of the buffer member, two buffer members among the four buffer members are spaced apart from each other and have the respective main surfaces disposed along each other, and the other two buffer members are spaced apart from each other and have the respective main surfaces disposed along each other, a frame shape is shown when viewed in a plan view from a direction orthogonal to a normal direction of all four main surfaces of the four buffer members, and in the plan view, an article is stored in a region surrounded by the four buffer members. 